基于仿真的TCP拥塞控制算法研究

Research on TCP Congestion Control Algorithms Based on Simulation

从数据包级研究了几种不同的TCP拥塞控制算法:Tahoe、Reno、Newreno、SACK,探讨了TCP增加选择性确认(SACK)和选择性重传的优点。通过对TCP协议版本的实验仿真,比较它们在相同的网络环境下算法的性能差异。当窗口中多个报文丢失,没有选择性确认机制的TCP Reno表现很差的性能。而在TCP Reno基础上做一个保守的扩展,将选择性确认机制加入到TCP中,TCP SACK表现出优异的性能:TCP SACK增强了TCP的鲁棒性,解决了报文失序的问题,提高了重发效率和信道的利用率。

This paper discusses several different TCP Congestion Control Algorithms such as Tahoe,Reno,Newreno,SACK in the level of the packet and also explores the benefits of adding selective acknowledgments（SACK） and selective repeat to TCP.Simulation results are used to compare the performance of TCP protocol under the same network conditions.In particular,when multiple packages are dropped from a window of data,TCP Reno without selective acknowledgments achieves badly ultimate performance.A conservative extension of TCP Reno is modified to use the selective acknowledgments option,highlight performance is achieved by TCP SACK.The SACK implementation could be improved in its robustness to reordered packages and retransmission efficiency and channel utilization.